How to prevent your roof covering deteriorating through years of UV radiation


Is your roof exposed to the merciless rays of the sun every year? You might think that over time, the roof would be damaged by UV radiation. Ultraviolet radiation, or UV light, has various negative effects. For example, not only does it cause our skin to age, but also various types of plastic. That’s why choosing the right roofing material is essential. Discover in this article the products you can have complete confidence in!


In principle, UV radiation causes flat roofs to age. Bitumen roofs are exposed to various weather conditions throughout the year, including harsh solar radiation.

Back in the day, there was no modified bitumen. Tar was primarily used as a roof covering. Under exposure to UV radiation, tar melted, became brittle and small cracks appeared in it. In order to counteract these effects, stone chippings were then applied as a coating on the roof covering. As a result, the bitumen waterproofing was not directly exposed to the UV radiation.


These days, modified bitumen is available, which is much more resistant to UV radiation. For example, you can find roof sheets that are finished with slate chippings or granulates. Another important aspect: APP is more resistant to UV radiation than SBS, given that a lot of plastic is added to APP. This plastic provides better protection against exposure to UV radiation.

For roof sheets in SBS there is another solution: the membranes are finished with slate chippings or granulate, with a protective ALSAN ReflectRoof coating that ensures optimal reflection and reduced heating of the roof surface or – as it used to be – with stone chippings.

For optimum protection of the roof surface, you can also opt for a green roof. This not only protects the membrane but also acts as a buffer for the rainwater.


You can also choose plastic membranes from the Flag range. The plastic membrane TPO from SOPREMA is extremely resistant against UV radiation. This product does not contain any plasticisers meaning that the roof sheets remain elastic. In addition, no cracks can occur in the membrane.

In fact, the lighter the colour of the membrane (e.g. light grey or white), the better the reflection value. As a result, the temperature on the roof will be lower, and the roof will therefore be less exposed to thermal shocks.

Would you like more information about protecting flat roofs against UV radiation? Contact us now!